[PATCH] sysrq cleanup

sysrq.c is fairly revolting.  Fix.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 115 insertions, 135 deletions

diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index d58f82318853..35082dc12eae 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -42,16 +42,15 @@
 /* Whether we react on sysrq keys or just ignore them */
 int sysrq_enabled = 1;
 
-/* Loglevel sysrq handler */
 static void sysrq_handle_loglevel(int key, struct pt_regs *pt_regs,
-                                  struct tty_struct *tty) 
+                                  struct tty_struct *tty)
 {
         int i;
         i = key - '0';
         console_loglevel = 7;
         printk("Loglevel set to %d\n", i);
         console_loglevel = i;
-}       
+}
 static struct sysrq_key_op sysrq_loglevel_op = {
         .handler        = sysrq_handle_loglevel,
         .help_msg       = "loglevel0-8",
@@ -59,11 +58,9 @@ static struct sysrq_key_op sysrq_loglevel_op = {
         .enable_mask    = SYSRQ_ENABLE_LOG,
 };
 
-
-/* SAK sysrq handler */
 #ifdef CONFIG_VT
 static void sysrq_handle_SAK(int key, struct pt_regs *pt_regs,
-                             struct tty_struct *tty) 
+                             struct tty_struct *tty)
 {
         if (tty)
                 do_SAK(tty);
@@ -75,12 +72,13 @@ static struct sysrq_key_op sysrq_SAK_op = {
         .action_msg     = "SAK",
         .enable_mask    = SYSRQ_ENABLE_KEYBOARD,
 };
+#else
+#define sysrq_SAK_op (*(struct sysrq_key_op *)0)
 #endif
 
 #ifdef CONFIG_VT
-/* unraw sysrq handler */
 static void sysrq_handle_unraw(int key, struct pt_regs *pt_regs,
-                               struct tty_struct *tty) 
+                               struct tty_struct *tty)
 {
         struct kbd_struct *kbd = &kbd_table[fg_console];
 
@@ -93,10 +91,11 @@ static struct sysrq_key_op sysrq_unraw_op = {
         .action_msg     = "Keyboard mode set to XLATE",
         .enable_mask    = SYSRQ_ENABLE_KEYBOARD,
 };
+#else
+#define sysrq_unraw_op (*(struct sysrq_key_op *)0)
 #endif /* CONFIG_VT */
 
 #ifdef CONFIG_KEXEC
-/* crashdump sysrq handler */
 static void sysrq_handle_crashdump(int key, struct pt_regs *pt_regs,
                                 struct tty_struct *tty)
 {
@@ -108,16 +107,16 @@ static struct sysrq_key_op sysrq_crashdump_op = {
         .action_msg     = "Trigger a crashdump",
         .enable_mask    = SYSRQ_ENABLE_DUMP,
 };
+#else
+#define sysrq_crashdump_op (*(struct sysrq_key_op *)0)
 #endif
 
-/* reboot sysrq handler */
 static void sysrq_handle_reboot(int key, struct pt_regs *pt_regs,
-                                struct tty_struct *tty) 
+                                struct tty_struct *tty)
 {
         local_irq_enable();
         emergency_restart();
 }
-
 static struct sysrq_key_op sysrq_reboot_op = {
         .handler        = sysrq_handle_reboot,
         .help_msg       = "reBoot",
@@ -126,11 +125,10 @@ static struct sysrq_key_op sysrq_reboot_op = {
 };
 
 static void sysrq_handle_sync(int key, struct pt_regs *pt_regs,
-                              struct tty_struct *tty) 
+                              struct tty_struct *tty)
 {
         emergency_sync();
 }
-
 static struct sysrq_key_op sysrq_sync_op = {
         .handler        = sysrq_handle_sync,
         .help_msg       = "Sync",
@@ -139,11 +137,10 @@ static struct sysrq_key_op sysrq_sync_op = {
 };
 
 static void sysrq_handle_mountro(int key, struct pt_regs *pt_regs,
-                                 struct tty_struct *tty) 
+                                 struct tty_struct *tty)
 {
         emergency_remount();
 }
-
 static struct sysrq_key_op sysrq_mountro_op = {
         .handler        = sysrq_handle_mountro,
         .help_msg       = "Unmount",
@@ -151,28 +148,23 @@ static struct sysrq_key_op sysrq_mountro_op = {
         .enable_mask    = SYSRQ_ENABLE_REMOUNT,
 };
 
-/* END SYNC SYSRQ HANDLERS BLOCK */
-
 #ifdef CONFIG_DEBUG_MUTEXES
-
-static void
-sysrq_handle_showlocks(int key, struct pt_regs *pt_regs, struct tty_struct *tty)
+static void sysrq_handle_showlocks(int key, struct pt_regs *pt_regs,
+                                struct tty_struct *tty)
 {
         mutex_debug_show_all_locks();
 }
-
 static struct sysrq_key_op sysrq_showlocks_op = {
         .handler        = sysrq_handle_showlocks,
         .help_msg       = "show-all-locks(D)",
         .action_msg     = "Show Locks Held",
 };
-
+#else
+#define sysrq_showlocks_op (*(struct sysrq_key_op *)0)
 #endif
 
-/* SHOW SYSRQ HANDLERS BLOCK */
-
 static void sysrq_handle_showregs(int key, struct pt_regs *pt_regs,
-                                  struct tty_struct *tty) 
+                                  struct tty_struct *tty)
 {
         if (pt_regs)
                 show_regs(pt_regs);
@@ -184,9 +176,8 @@ static struct sysrq_key_op sysrq_showregs_op = {
         .enable_mask    = SYSRQ_ENABLE_DUMP,
 };
 
-
 static void sysrq_handle_showstate(int key, struct pt_regs *pt_regs,
-                                   struct tty_struct *tty) 
+                                   struct tty_struct *tty)
 {
         show_state();
 }
@@ -197,9 +188,8 @@ static struct sysrq_key_op sysrq_showstate_op = {
         .enable_mask    = SYSRQ_ENABLE_DUMP,
 };
 
-
 static void sysrq_handle_showmem(int key, struct pt_regs *pt_regs,
-                                 struct tty_struct *tty) 
+                                 struct tty_struct *tty)
 {
         show_mem();
 }
@@ -210,13 +200,9 @@ static struct sysrq_key_op sysrq_showmem_op = {
         .enable_mask    = SYSRQ_ENABLE_DUMP,
 };
 
-/* SHOW SYSRQ HANDLERS BLOCK */
-
-
-/* SIGNAL SYSRQ HANDLERS BLOCK */
-
-/* signal sysrq helper function
- * Sends a signal to all user processes */
+/*
+ * Signal sysrq helper function.  Sends a signal to all user processes.
+ */
 static void send_sig_all(int sig)
 {
         struct task_struct *p;
@@ -229,7 +215,7 @@ static void send_sig_all(int sig)
 }
 
 static void sysrq_handle_term(int key, struct pt_regs *pt_regs,
-                              struct tty_struct *tty) 
+                              struct tty_struct *tty)
 {
         send_sig_all(SIGTERM);
         console_loglevel = 8;
@@ -243,7 +229,8 @@ static struct sysrq_key_op sysrq_term_op = {
 
 static void moom_callback(void *ignored)
 {
-        out_of_memory(&NODE_DATA(0)->node_zonelists[ZONE_NORMAL], GFP_KERNEL, 0);
+        out_of_memory(&NODE_DATA(0)->node_zonelists[ZONE_NORMAL],
+                        GFP_KERNEL, 0);
 }
 
 static DECLARE_WORK(moom_work, moom_callback, NULL);
@@ -260,7 +247,7 @@ static struct sysrq_key_op sysrq_moom_op = {
 };
 
 static void sysrq_handle_kill(int key, struct pt_regs *pt_regs,
-                              struct tty_struct *tty) 
+                              struct tty_struct *tty)
 {
         send_sig_all(SIGKILL);
         console_loglevel = 8;
@@ -272,8 +259,6 @@ static struct sysrq_key_op sysrq_kill_op = {
         .enable_mask    = SYSRQ_ENABLE_SIGNAL,
 };
 
-/* END SIGNAL SYSRQ HANDLERS BLOCK */
-
 static void sysrq_handle_unrt(int key, struct pt_regs *pt_regs,
                                 struct tty_struct *tty)
 {
@@ -288,110 +273,99 @@ static struct sysrq_key_op sysrq_unrt_op = {
 
 /* Key Operations table and lock */
 static DEFINE_SPINLOCK(sysrq_key_table_lock);
-#define SYSRQ_KEY_TABLE_LENGTH 36
-static struct sysrq_key_op *sysrq_key_table[SYSRQ_KEY_TABLE_LENGTH] = {
-/* 0 */ &sysrq_loglevel_op,
-/* 1 */ &sysrq_loglevel_op,
-/* 2 */ &sysrq_loglevel_op,
-/* 3 */ &sysrq_loglevel_op,
-/* 4 */ &sysrq_loglevel_op,
-/* 5 */ &sysrq_loglevel_op,
-/* 6 */ &sysrq_loglevel_op,
-/* 7 */ &sysrq_loglevel_op,
-/* 8 */ &sysrq_loglevel_op,
-/* 9 */ &sysrq_loglevel_op,
-/* a */ NULL, /* Don't use for system provided sysrqs,
-                 it is handled specially on the sparc
-                 and will never arrive */
-/* b */ &sysrq_reboot_op,
-#ifdef CONFIG_KEXEC
-/* c */ &sysrq_crashdump_op,
-#else
-/* c */ NULL,
-#endif
-#ifdef CONFIG_DEBUG_MUTEXES
-/* d */ &sysrq_showlocks_op,
-#else
-/* d */ NULL,
-#endif
-/* e */ &sysrq_term_op,
-/* f */ &sysrq_moom_op,
-/* g */ NULL,
-/* h */ NULL,
-/* i */ &sysrq_kill_op,
-/* j */ NULL,
-#ifdef CONFIG_VT
-/* k */ &sysrq_SAK_op,
-#else
-/* k */ NULL,
-#endif
-/* l */ NULL,
-/* m */ &sysrq_showmem_op,
-/* n */ &sysrq_unrt_op,
-/* o */ NULL, /* This will often be registered
-                 as 'Off' at init time */
-/* p */ &sysrq_showregs_op,
-/* q */ NULL,
-#ifdef CONFIG_VT
-/* r */ &sysrq_unraw_op,
-#else
-/* r */ NULL,
-#endif
-/* s */ &sysrq_sync_op,
-/* t */ &sysrq_showstate_op,
-/* u */ &sysrq_mountro_op,
-/* v */ NULL, /* May be assigned at init time by SMP VOYAGER */
-/* w */ NULL,
-/* x */ NULL,
-/* y */ NULL,
-/* z */ NULL
+
+static struct sysrq_key_op *sysrq_key_table[36] = {
+        &sysrq_loglevel_op,             /* 0 */
+        &sysrq_loglevel_op,             /* 1 */
+        &sysrq_loglevel_op,             /* 2 */
+        &sysrq_loglevel_op,             /* 3 */
+        &sysrq_loglevel_op,             /* 4 */
+        &sysrq_loglevel_op,             /* 5 */
+        &sysrq_loglevel_op,             /* 6 */
+        &sysrq_loglevel_op,             /* 7 */
+        &sysrq_loglevel_op,             /* 8 */
+        &sysrq_loglevel_op,             /* 9 */
+
+        /*
+         * Don't use for system provided sysrqs, it is handled specially on
+         * sparc and will never arrive
+         */
+        NULL,                           /* a */
+        &sysrq_reboot_op,               /* b */
+        &sysrq_crashdump_op,            /* c */
+        &sysrq_showlocks_op,            /* d */
+        &sysrq_term_op,                 /* e */
+        &sysrq_moom_op,                 /* f */
+        NULL,                           /* g */
+        NULL,                           /* h */
+        &sysrq_kill_op,                 /* i */
+        NULL,                           /* j */
+        &sysrq_SAK_op,                  /* k */
+        NULL,                           /* l */
+        &sysrq_showmem_op,              /* m */
+        &sysrq_unrt_op,                 /* n */
+        /* This will often be registered as 'Off' at init time */
+        NULL,                           /* o */
+        &sysrq_showregs_op,             /* p */
+        NULL,                           /* q */
+        &sysrq_unraw_op,                        /* r */
+        &sysrq_sync_op,                 /* s */
+        &sysrq_showstate_op,            /* t */
+        &sysrq_mountro_op,              /* u */
+        /* May be assigned at init time by SMP VOYAGER */
+        NULL,                           /* v */
+        NULL,                           /* w */
+        NULL,                           /* x */
+        NULL,                           /* y */
+        NULL                            /* z */
 };
 
 /* key2index calculation, -1 on invalid index */
-static int sysrq_key_table_key2index(int key) {
+static int sysrq_key_table_key2index(int key)
+{
         int retval;
-        if ((key >= '0') && (key <= '9')) {
+
+        if ((key >= '0') && (key <= '9'))
                 retval = key - '0';
-        } else if ((key >= 'a') && (key <= 'z')) {
+        else if ((key >= 'a') && (key <= 'z'))
                 retval = key + 10 - 'a';
-        } else {
+        else
                 retval = -1;
-        }
         return retval;
 }
 
 /*
  * get and put functions for the table, exposed to modules.
  */
-
-struct sysrq_key_op *__sysrq_get_key_op (int key) {
-        struct sysrq_key_op *op_p;
+struct sysrq_key_op *__sysrq_get_key_op(int key)
+{
+        struct sysrq_key_op *op_p = NULL;
         int i;
-        
+
         i = sysrq_key_table_key2index(key);
-        op_p = (i == -1) ? NULL : sysrq_key_table[i];
+        if (i != -1)
+                op_p = sysrq_key_table[i];
         return op_p;
 }
 
-static void __sysrq_put_key_op (int key, struct sysrq_key_op *op_p) {
-        int i;
+static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
+{
+        int i = sysrq_key_table_key2index(key);
 
-        i = sysrq_key_table_key2index(key);
         if (i != -1)
                 sysrq_key_table[i] = op_p;
 }
 
 /*
- * This is the non-locking version of handle_sysrq
- * It must/can only be called by sysrq key handlers,
- * as they are inside of the lock
+ * This is the non-locking version of handle_sysrq.  It must/can only be called
+ * by sysrq key handlers, as they are inside of the lock
  */
-
-void __handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty, int check_mask)
+void __handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty,
+                        int check_mask)
 {
         struct sysrq_key_op *op_p;
         int orig_log_level;
-        int i, j;
+        int i;
         unsigned long flags;
 
         spin_lock_irqsave(&sysrq_key_table_lock, flags);
@@ -401,26 +375,34 @@ void __handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty, in
 
         op_p = __sysrq_get_key_op(key);
         if (op_p) {
-                /* Should we check for enabled operations (/proc/sysrq-trigger should not)
-                 * and is the invoked operation enabled? */
+                /*
+                 * Should we check for enabled operations (/proc/sysrq-trigger
+                 * should not) and is the invoked operation enabled?
+                 */
                 if (!check_mask || sysrq_enabled == 1 ||
                     (sysrq_enabled & op_p->enable_mask)) {
-                        printk ("%s\n", op_p->action_msg);
+                        printk("%s\n", op_p->action_msg);
                         console_loglevel = orig_log_level;
                         op_p->handler(key, pt_regs, tty);
-                }
-                else
+                } else {
                         printk("This sysrq operation is disabled.\n");
+                }
         } else {
                 printk("HELP : ");
                 /* Only print the help msg once per handler */
-                for (i=0; i<SYSRQ_KEY_TABLE_LENGTH; i++) 
-                if (sysrq_key_table[i]) {
-                        for (j=0; sysrq_key_table[i] != sysrq_key_table[j]; j++);
-                        if (j == i)
-                                printk ("%s ", sysrq_key_table[i]->help_msg);
+                for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
+                        if (sysrq_key_table[i]) {
+                                int j;
+
+                                for (j = 0; sysrq_key_table[i] !=
+                                                sysrq_key_table[j]; j++)
+                                        ;
+                                if (j != i)
+                                        continue;
+                                printk("%s ", sysrq_key_table[i]->help_msg);
+                        }
                 }
-                printk ("\n");
+                printk("\n");
                 console_loglevel = orig_log_level;
         }
         spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
@@ -430,16 +412,17 @@ void __handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty, in
  * This function is called by the keyboard handler when SysRq is pressed
  * and any other keycode arrives.
  */
-
 void handle_sysrq(int key, struct pt_regs *pt_regs, struct tty_struct *tty)
 {
         if (!sysrq_enabled)
                 return;
         __handle_sysrq(key, pt_regs, tty, 1);
 }
+EXPORT_SYMBOL(handle_sysrq);
 
 static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
-                                struct sysrq_key_op *remove_op_p) {
+                                struct sysrq_key_op *remove_op_p)
+{
 
         int retval;
         unsigned long flags;
@@ -452,7 +435,6 @@ static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
                 retval = -1;
         }
         spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
-
         return retval;
 }
 
@@ -460,12 +442,10 @@ int register_sysrq_key(int key, struct sysrq_key_op *op_p)
 {
         return __sysrq_swap_key_ops(key, op_p, NULL);
 }
+EXPORT_SYMBOL(register_sysrq_key);
 
 int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
 {
         return __sysrq_swap_key_ops(key, NULL, op_p);
 }
-
-EXPORT_SYMBOL(handle_sysrq);
-EXPORT_SYMBOL(register_sysrq_key);
 EXPORT_SYMBOL(unregister_sysrq_key);